Firearm with mounting means for ventilated thermoplastic rib



J1me 1966 w. L. DAHL ETAL 3,255,546

FIREARM WITH MOUNTING MEANS FOR VENTILATED THERMOPLASTIC RIB Filed Dec. 30, 1964 Fig. 3.

Fig. 2.

Inventors: Walter L. Dohl, Paul H. Eccleston,

Wayne E. Leek.

Their Attorneys.

United States Patent 3,255,546 FIREARM WITH MOUNTING MEANS FOR VENTILATED THERMOPLASTIC RIB Walter L. Dahl, Herkimer, Paul H. Eccleston, Frankfort,

and Wayne E. Leek, Ilion, N.Y., assignors to Remington Arms Company, Inc., Bridgeport, Conn., a corporation of Delaware Filed Dec. 30, 1964, Ser. No. 422,241 Claims. CI. 4276) This invention relates to a firearm having a ventilated rib attached to the barrel, and in particular, to the method of mounting the rib on the barrel.

Solid objects such as straps or bars hung on the outside of the barrel of a firearm and rigidly fastened tothe barrel interfere with accuracy due to heating up of the barrel during shooting. Because of this problem, socalled ventilated ribs are used on gun barrels. These ribs are fastened to the barrels at a few points only and provide air spaces between the main body of the rib and the barrel.

The increased use of synthetic materials in the firearms field has given rise to a number of structural problems. Thermoplastic structures have a tendency to creep under compression and therefore it is extremely difficult to mount any such devices on firearms. Thermoplastic articles also absorb moisture and expand causing buckling if the attachment is tight.

It is therefore the main object of this invention to provide a method of mounting a rib on a firearm barrel so that the rib floats on the barrel.

Another object of this invention is to provide a thermoplastic rib for firearms barrels.

A further object of this invention is to provide a method of mounting a thermoplastic rib for firearms barrels.

It is contemplated that these objectives may best be achieved by providing a firearm barrel with a series of studs and a thermoplastic rib designed to float on the studs. The rib is designed to eliminate creep so that no looseness will result between the sights, rib and barrel, while at the same time the stud is made slightly higher than the rib to insure that the rib floats. The sights are mounted above the rib.

It is to be understood that the embodiments of the invention to be disclosed are equally applicable to all firearms having ribs mounted on the barrel.

Other objects and advantages of this invention will become apparent as the following description proceeds, and

' the features of novelty which characterize this invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

In the drawings:

FIGURE 1 is a side elevation of a firearm incorporating this invention;

FIGURE 2 is a side elevation partially in section showing the thermoplastic rib mounted on the barrel; and

FIGURE 3 is a top elevation of a thermoplastic rib.

Reference may now be made to the drawings where it can be seen that in FIG. 1 a bolt action rifle 1 is shown with a thermoplastic rib 2 mounted on a barrel 3. While rib 2 may be mounted on any type of firearm, a bolt action rifle has been chosen in this instance.

Rifle 1 is a standard bolt action rifle having a stock 4, receiver 5, bolt 6, trigger 7 and of course barrel 3 mentioned above. Bolt 6 is provided with a bolt handle 8 for actuation of the firearm. For protect-ion and the like, a trigger guard 9 is mounted about trigger 7. The rifle is also provided with a rear sight 10 and a front sight 11 mounted above rib 2.

Rib 2 has a series of legs or down turned flanges 12 which rest on barrel 3. A number of screws '13 hold rib 3,255,546 Patented June 14, 1966 2 in place on barrel 3. Rear sight 10 is secured by screws 14, while front sight 11 is secured by screws 15.

As can be seen in FIG. 2, barrel 3 has a series of studs 16 attached to it by any suitable means such as brazing or preferably by projection welding. Studs 16 are spaced to correspond to elongated openings 17 formed in rib 2. The elongated openings 17 are made larger than studs 16 so that rib '2 will float on studs 16 and barrel 3.

Screws 1-3 have heads larger than openings 17 as shown in FIG. 2 to retain rib- 2 on barrel 3. Each stud has internal threads 18 to receive screws 13. Sights 10 and 11 are screwed directly to studs 16 also retaining rib 2 in place.

Preferably rib 2 is molded out of aceta'l resins sold under the trademark Delrin of the E. I. du Pont de Nemours and Company, Inc. Satisfactory ribs can be molded from nylon resins. Both of these thermoplastics tend to absorb moisture and expand therefrom. Thermoplastics under compression also tend to creep and thereby work loose. The expansion due to moisture also causes buckling and disturbance of sights on the rib with a corresponding effect on accuracy.

In order toovercorne these deficiencies, a new method of retaining a thermoplastic rib to a barrel had to be found. Rib 2 is molded with a number of legs 12 that bear on barrel 3 so that a series of air spaces 19 are provided for ventilation. Legs 12 are made slightly shorter than studs 16 so that screws 13 will retain but not compress rib 2.

When the thermoplastic is not compressed it does not creep and therefore will not become loose. Screws 13 are tightened directly to studs 16 retaining rib 2 on barrel 3 without compression. Openings 17 being larger in diameter than studs 16 allow expansion and contraction of both rib 2 and barrel 3 without binding or buckling.

In order to insure that rib 2 floats on studs 16 and barrel 3, studs '16 are made preferably 0.015" higher than rib 2. It has been found that the dimension can be from 0.010" to 0.020".

While rib 2 may be molded with a smooth top surface, this can lead to a reflective surface disturbing the sight line. To overcome this difliculty it is preferred to mold rib 2 with a matted top surface section 20 as shown in FIG. 3.

What is claimed is:

1. In a firearm having a barrel, a receiver to which said barrel is secured, a breech bolt reciprocally mounted in said receiver, the improvement comprising a thermoplastic rib mounted on said barrel, said rib being molded with a plurality of elongated openings and a plurality of flanges, said barrel having a plurality of studs secured therto, said openings arranged to coincide with and be larger than said studs, said flanges arranged to engage said barrel, screws attached to said studs to maintain said rib on said barrel, said studs being higher than said flanges, whereby said rib floats between said screws and said barrel.

2. In a firearm having a barrel, a receiver to which said barrel is secured, a breech bolt reciprocally mounted in said receiver, the improvement comprising a thermoplastic rib mounted on said barrel, said rib being molded with a plurality of elongated openings and a plurality of flanges, said barrel having a plurality of studs secured thereto, said openings arranged to coincide with and be larger than said studs, said flanges arranged to engage said barrel, screw-s attached to said studs to maintain said rib on said barrel, said studs being 0.015" higher than said flanges whereby said rib floats between said screws and said barrel.

3. In a firearm having a barrel, a receiver to which said barrel is secured, a breech bolt reciprocally mounted in said receiver, the improvement comprising a thermoplastic rib mounted on said barrel, said rib being molded with a plurality of elongated openings and a plurality of flanges, said barrel having a plurality of studs secured thereto, said openings arranged to coincide with and be larger than said studs, said flanges arranged to engage said barrel, screws attached to said studs to maintain said rib on said barrel, said studs being at least 0.010 higher than said flanges whereby said rib floats between said screws and said barrel.

4. In a firearm having a barrel, a receiver to which said barrel is secured, a breech bolt reciprocally mounted in said receiver, the improvement comprising a thermoplastic rib mounted on said barrel, said rib being molded With a plurality of elongated openings and a plurality of flanges, said barrel having a plurality of studs secured thereto, said openings arranged to coincide with and be larger than said studs, said flanges arranged to engage said barrel, screws attached to said studs to maintain said rib on said barrel, said studs being no more than 0.020" higher than said flanges whereby said rib floats between said screws and said barrel.

5. In a firearm having a barrel, a receiver to which said barrel is secured, a breech bolt reciprocally mounted in said receiver, the improvement comprising a thermoplastic rib mounted on said barrel, said rib being molded with a plurality of elongated openings and a plurality of flanges, said barrel having a plurality of studs secured thereto, said openings arranged to coincide with and be larger than said studs, said flanges arranged to engage said barrel, sights attached to at least two of said studs to maintain said rib on said barrel, said studs being higher than said flanges whereby said rib floats between said sights and said barrel.

References Cited by the Examiner UNITED STATES PATENTS 1,137,477 4/1915 Godshalk 4276 X 2,496,854 2/1950 Crank 4276 2,929,164 3/1960 Browning 4276 3,107,450 10/1963 Snyder et al. 4276 BENJAMIN A. BORCHELT, Primary Examiner. 

1. IN A FIREARM HAVING A BARREL, A RECEIVER TO WHICH SAID BARREL IS SECURED, A BREECH BOLT RECIPROCALLY MOUNTED IN SAID RECEIVER, THE IMPROVEMENT COMPRISING A THERMOPLASTIC RIB MOUNTED ON SAID BARREL, SAID RIOB BEING MOLDED WITH A PLURALITY OF ELONGATED OPENINGS AND A PLURALITY OF FLANGES, SAID BARREL HAVING A PLURALITY OF STUDS SECURED THERETO, SAID OPENINGS ARRANGED TO COINCIDE WITH AND BE LARGER THAN SAID STUDS, SAID FLANGES ARRANGES TO ENGAGE SAID BARREL, SCREWS ATTACHED TO SAID STUDS TO MAINTAIN SAID RIB ON SAID BARREL, SAID STUDS BEING HIGHER THAN SAID FLANGES, WHEREBY SAID RIB FLOATS BETWEEN SAID SCREWS AND SAID BARREL. 